Various polymers that contain cyclic structures in a main chain have been known. For example, Patent Literature 1 discloses a polymer that contains, in a main chain, a cyclopentane-1,3-diyl structure obtained by using an unconjugated diene compound as a monomer. Further, Patent Literature 2 discloses a polymer that contains, in a main chain, a cyclohexane-1,3-diyl structure obtained by using an unconjugated diene compound as a monomer. Furthermore, Patent Literature 3 discloses a cyclohexene addition polymer obtained by polymerization of a cyclohexene monomer with use of a catalyst made of a transition metal compound, an alkylaluminoxane and a boron compound.